/Engine/Source/Runtime/Engine/Public/ViewportClient.h
Check a gesture event received by the viewport. If the viewport client uses the event, it should return true to consume it.
True to consume the gesture event, false to pass it on.
virtual bool InputGesture ( [FViewport](API\Runtime\Engine\FViewport) * Viewport, EGestureEvent GestureType, const FVector2D & GestureDelta, bool bIsDirectionInvertedFromDevice )